//---------------------------------------------------------------------- // ParseCompileUnitDIEsIfNeeded // // Parses a compile unit and indexes its DIEs if it hasn't already been // done. //---------------------------------------------------------------------- size_t DWARFCompileUnit::ExtractDIEsIfNeeded (bool cu_die_only) { const size_t initial_die_array_size = m_die_array.size(); if ((cu_die_only && initial_die_array_size > 0) || initial_die_array_size > 1) return 0; // Already parsed Timer scoped_timer (__PRETTY_FUNCTION__, "%8.8x: DWARFCompileUnit::ExtractDIEsIfNeeded( cu_die_only = %i )", m_offset, cu_die_only); // Set the offset to that of the first DIE and calculate the start of the // next compilation unit header. lldb::offset_t offset = GetFirstDIEOffset(); lldb::offset_t next_cu_offset = GetNextCompileUnitOffset(); DWARFDebugInfoEntry die; // Keep a flat array of the DIE for binary lookup by DIE offset if (!cu_die_only) { Log *log (LogChannelDWARF::GetLogIfAny(DWARF_LOG_DEBUG_INFO | DWARF_LOG_LOOKUPS)); if (log) { m_dwarf2Data->GetObjectFile()->GetModule()->LogMessageVerboseBacktrace (log, "DWARFCompileUnit::ExtractDIEsIfNeeded () for compile unit at .debug_info[0x%8.8x]", GetOffset()); } } uint32_t depth = 0; // We are in our compile unit, parse starting at the offset // we were told to parse const DWARFDataExtractor& debug_info_data = m_dwarf2Data->get_debug_info_data(); std::vector<uint32_t> die_index_stack; die_index_stack.reserve(32); die_index_stack.push_back(0); bool prev_die_had_children = false; DWARFFormValue::FixedFormSizes fixed_form_sizes = DWARFFormValue::GetFixedFormSizesForAddressSize (GetAddressByteSize(), m_is_dwarf64); while (offset < next_cu_offset && die.FastExtract (debug_info_data, this, fixed_form_sizes, &offset)) { // if (log) // log->Printf("0x%8.8x: %*.*s%s%s", // die.GetOffset(), // depth * 2, depth * 2, "", // DW_TAG_value_to_name (die.Tag()), // die.HasChildren() ? " *" : ""); const bool null_die = die.IsNULL(); if (depth == 0) { uint64_t base_addr = die.GetAttributeValueAsUnsigned(m_dwarf2Data, this, DW_AT_low_pc, LLDB_INVALID_ADDRESS); if (base_addr == LLDB_INVALID_ADDRESS) base_addr = die.GetAttributeValueAsUnsigned(m_dwarf2Data, this, DW_AT_entry_pc, 0); SetBaseAddress (base_addr); if (initial_die_array_size == 0) AddDIE (die); if (cu_die_only) return 1; } else { if (null_die) { if (prev_die_had_children) { // This will only happen if a DIE says is has children // but all it contains is a NULL tag. Since we are removing // the NULL DIEs from the list (saves up to 25% in C++ code), // we need a way to let the DIE know that it actually doesn't // have children. if (!m_die_array.empty()) m_die_array.back().SetEmptyChildren(true); } } else { die.SetParentIndex(m_die_array.size() - die_index_stack[depth-1]); if (die_index_stack.back()) m_die_array[die_index_stack.back()].SetSiblingIndex(m_die_array.size()-die_index_stack.back()); // Only push the DIE if it isn't a NULL DIE m_die_array.push_back(die); } } if (null_die) { // NULL DIE. if (!die_index_stack.empty()) die_index_stack.pop_back(); if (depth > 0) --depth; if (depth == 0) break; // We are done with this compile unit! prev_die_had_children = false; } else { die_index_stack.back() = m_die_array.size() - 1; // Normal DIE const bool die_has_children = die.HasChildren(); if (die_has_children) { die_index_stack.push_back(0); ++depth; } prev_die_had_children = die_has_children; } } // Give a little bit of info if we encounter corrupt DWARF (our offset // should always terminate at or before the start of the next compilation // unit header). if (offset > next_cu_offset) { m_dwarf2Data->GetObjectFile()->GetModule()->ReportWarning ("DWARF compile unit extends beyond its bounds cu 0x%8.8x at 0x%8.8" PRIx64 "\n", GetOffset(), offset); } // Since std::vector objects will double their size, we really need to // make a new array with the perfect size so we don't end up wasting // space. So here we copy and swap to make sure we don't have any extra // memory taken up. if (m_die_array.size () < m_die_array.capacity()) { DWARFDebugInfoEntry::collection exact_size_die_array (m_die_array.begin(), m_die_array.end()); exact_size_die_array.swap (m_die_array); } Log *verbose_log (LogChannelDWARF::GetLogIfAll (DWARF_LOG_DEBUG_INFO | DWARF_LOG_VERBOSE)); if (verbose_log) { StreamString strm; Dump(&strm); if (m_die_array.empty()) strm.Printf("error: no DIE for compile unit"); else m_die_array[0].Dump(m_dwarf2Data, this, strm, UINT32_MAX); verbose_log->PutCString (strm.GetString().c_str()); } return m_die_array.size(); }
// Parses a compile unit and indexes its DIEs, m_die_array_mutex must be // held R/W and m_die_array must be empty. void DWARFUnit::ExtractDIEsRWLocked() { llvm::sys::ScopedWriter first_die_lock(m_first_die_mutex); static Timer::Category func_cat(LLVM_PRETTY_FUNCTION); Timer scoped_timer( func_cat, "%8.8x: DWARFUnit::ExtractDIEsIfNeeded()", m_offset); // Set the offset to that of the first DIE and calculate the start of the // next compilation unit header. lldb::offset_t offset = GetFirstDIEOffset(); lldb::offset_t next_cu_offset = GetNextCompileUnitOffset(); DWARFDebugInfoEntry die; uint32_t depth = 0; // We are in our compile unit, parse starting at the offset we were told to // parse const DWARFDataExtractor &data = GetData(); std::vector<uint32_t> die_index_stack; die_index_stack.reserve(32); die_index_stack.push_back(0); bool prev_die_had_children = false; DWARFFormValue::FixedFormSizes fixed_form_sizes = DWARFFormValue::GetFixedFormSizesForAddressSize(GetAddressByteSize()); while (offset < next_cu_offset && die.FastExtract(data, this, fixed_form_sizes, &offset)) { const bool null_die = die.IsNULL(); if (depth == 0) { assert(m_die_array.empty() && "Compile unit DIE already added"); // The average bytes per DIE entry has been seen to be around 14-20 so // lets pre-reserve half of that since we are now stripping the NULL // tags. // Only reserve the memory if we are adding children of the main // compile unit DIE. The compile unit DIE is always the first entry, so // if our size is 1, then we are adding the first compile unit child // DIE and should reserve the memory. m_die_array.reserve(GetDebugInfoSize() / 24); m_die_array.push_back(die); if (!m_first_die) AddUnitDIE(m_die_array.front()); } else { if (null_die) { if (prev_die_had_children) { // This will only happen if a DIE says is has children but all it // contains is a NULL tag. Since we are removing the NULL DIEs from // the list (saves up to 25% in C++ code), we need a way to let the // DIE know that it actually doesn't have children. if (!m_die_array.empty()) m_die_array.back().SetHasChildren(false); } } else { die.SetParentIndex(m_die_array.size() - die_index_stack[depth - 1]); if (die_index_stack.back()) m_die_array[die_index_stack.back()].SetSiblingIndex( m_die_array.size() - die_index_stack.back()); // Only push the DIE if it isn't a NULL DIE m_die_array.push_back(die); } } if (null_die) { // NULL DIE. if (!die_index_stack.empty()) die_index_stack.pop_back(); if (depth > 0) --depth; prev_die_had_children = false; } else { die_index_stack.back() = m_die_array.size() - 1; // Normal DIE const bool die_has_children = die.HasChildren(); if (die_has_children) { die_index_stack.push_back(0); ++depth; } prev_die_had_children = die_has_children; } if (depth == 0) break; // We are done with this compile unit! } if (!m_die_array.empty()) { if (m_first_die) { // Only needed for the assertion. m_first_die.SetHasChildren(m_die_array.front().HasChildren()); lldbassert(m_first_die == m_die_array.front()); } m_first_die = m_die_array.front(); } m_die_array.shrink_to_fit(); if (m_dwo_symbol_file) { DWARFUnit *dwo_cu = m_dwo_symbol_file->GetCompileUnit(); dwo_cu->ExtractDIEsIfNeeded(); } }